1. Field of the Invention
The present invention relates to a contents information encryption system for recording and reproducing enciphered contents information enciphered with a predetermined contents key and enciphered key information obtained by enciphering the contents key for use in the enciphered contents information by using media ID as ID key.
An object of the present invention is to provide a contents information recording method for contents information enciphering system which distributes contents information (particularly audio and video data) and enables users to transfer the distributed data between media while preventing illegal transfer (move) and duplication thereof, and contents information processing unit, contents information deciphering method, contents information deciphering unit and media thereof.
2. Description of the Background Art
With a progress of enciphering technology, digital contents distribution management method, digital contents reproduction method and apparatus therefor have been proposed in Japanese Patent Application Laid-Open No. 10-269289 as an effective method for distributing audio or video digital data through network. According to the present invention, a distribution side of digital contents processes and compresses digital contents and sends the processed digital contents, enciphered contents key and enciphered accounting information to communication receivers. Money collected based on contents use information sent from the communication receivers is distributed to privilege persons. On the other hand, a digital contents reproducing side deciphers that processed digital contents with the contents key and simultaneously expands it to reproduce the original data. Then, data on charge money depending on use of the contents and contents use information are sent to the contents information distribution side. The recorded contents can be carried away to other places.
Further, Japanese Patent Application Laid-Open No. 9-25303 has disclosed an information recording media, recording unit, information transmission system and deciphering unit. The information recording media of the present invention contains enciphered information and enciphered key information obtained by enciphering key information for deciphering this enciphered information to its original information. Further, it contains condition information for deciphering the aforementioned enciphered information in a non-enciphered state. That is, because device information and region information are included in control information of the enciphered key information, duplication of the enciphered information into HDD or optical disk on user side for illegal use is prevented.
However, according to the above conventional described system, because media in which the contents data is recorded cannot be transferred between users (although the media itself can be transferred, the contents data recorded in that media cannot be reproduced properly), user needs to connect account control center, data management center or the like at least once in order to receive the contents data. Further, when a person has plural kinds of media, he cannot move data between the media or return the data to any medium after backup of the data while preventing illegal transfer and duplication.
Accordingly, an object of the present invention is to provide a contents information recording method, contents information processing unit, contents information deciphering method, contents information deciphering unit and media in contents information encryption system which distributes contents information and enables user to transfer (move) data between media while preventing illegal transfer and duplication of the distributed data.
To achieve the above object, there is provided a contents information recording method for recording enciphered contents information and enciphered key information from a first medium which records the enciphered contents information enciphered with a predetermined contents key and enciphered key information obtained by enciphering the contents key with information about media ID of the first medium as an ID key into a second medium, the method comprising the steps of: recording temporarily information about the media ID of the first medium in a predetermined memory other than the first and second media, recording the enciphered contents information and the enciphered key information the second medium, and deleting the enciphered key information from the first medium; and recording, in the second medium, independent ID information comprised of information about media ID of the second medium and media ID of the first medium recorded temporarily in the memory and deleting, from the memory, information about media ID of the first media recorded temporarily.
Further, to achieve the above object, there is provided a contents information recording method for recording enciphered contents information and enciphered key information from a first medium which records the enciphered contents information enciphered with a predetermined contents key and enciphered key information obtained by enciphering the contents key with information about media ID of the first medium as an ID key into a second medium, the method comprising the steps of: recording temporarily information about media ID of the first medium in a predetermined memory other than the first and second media in a condition that the information about the media ID corresponds to data link ID; recording the enciphered contents information, the enciphered key information and the data link ID in the second medium and deleting the enciphered key information from the first medium; and obtaining, based on the data link read out from the second medium, information about media ID of the first medium recorded temporarily in the memory, recording independent ID information comprised of information about media ID of the first medium and information about media ID of the second medium in the second medium, and deleting, from the memory, the information about media ID of the first medium recorded temporarily.
Still further, to achieve the above object, there is provided a contents information recording method for recording enciphered contents information and enciphered key information from a first medium which records the enciphered contents information enciphered with a predetermined contents key and enciphered key information obtained by enciphering the contents key with information about media ID of the first medium as an ID key into a second medium, the method comprising the steps of: recording temporarily information about media ID of the first medium and the enciphered key information in a predetermined memory other than the first and second media in a condition that the information about the media ID and the enciphered key information correspond to data link ID; recording the enciphered contents information, the enciphered key information and the data link ID in the second medium and deleting the enciphered key information from the first medium; obtaining, based on the data link ID read out from the second medium, information about media ID of the first medium recorded temporarily in the memory and the enciphered key information; and comparing the enciphered key information read from the second medium and the enciphered key information read from the memory with each other, and only when the two enciphered key informations coincide, recording independent ID information comprised of information about media ID of the second medium and information about media ID of the first medium read out from the memory in the second medium and deleting, from the memory, information about media ID of the first medium recorded temporarily and the enciphered key information.
According to a preferred embodiment of the present invention, information about media ID of the first media recorded temporarily in the memory is information based on media ID of the first medium read out from the first medium, and information about media ID of the second media is information based on media ID of the second medium read out from the second medium.
According to another preferred embodiment of the present invention, the independent ID information is differential ID information which is a differential value between media ID of the first medium and media ID of the second medium.
According to still another preferred embodiment of the present invention, the predetermined contents key is common key or public key, and the ID key is common key using media ID of the first medium or common key using information obtained by converting the media ID of the first medium with a predetermined function.
To achieve the above object, there is provided a contents information processing unit comprising: a memory for temporarily storing information about media ID of a first medium; an independent ID information forming means for forming independent ID information from information about media ID of a second medium and information about media ID of the first medium recorded temporarily in the memory and recording the independent ID information in the second medium; and a deleting means for, after the independent ID information is formed, deleting, from the memory, information about media ID of the first medium recorded temporarily.
According to a preferred embodiment of the present invention, information about media ID of the first media recorded temporarily in the memory is information based on media ID of the first medium read out from the first medium, and information about media ID of the second media is information based on media ID of the second medium read out from the second medium.
According to another preferred embodiment of the present invention, the independent ID information is differential ID information which is a differential value between media ID of the first medium and media ID of the second medium.
To achieve the above object, there is provided a contents information processing unit for processing information about ID of each medium upon recording enciphered contents information and enciphered key information from a first medium which records the enciphered contents information enciphered with a predetermined contents key and enciphered key information obtained by enciphering the contents key with information about media ID of the first medium as an ID key into a second medium, the contents information processing unit comprising: a memory for temporarily storing information about media ID of the first medium; an independent ID information forming means for forming independent ID information from information about media ID of the second medium and information about media ID of the first medium recorded temporarily in the memory and after the enciphered contents information and the enciphered key information are recorded in the second medium, recording the independent ID information in the second medium; and a deleting means for, after the independent ID information is formed, deleting, from the memory, information about media ID of the first medium recorded temporarily.
Further, to achieve the above object, there is provided a contents information processing unit for processing information about ID of each medium upon recording enciphered contents information and enciphered key information from a first medium which records the enciphered contents information enciphered with a predetermined contents key and enciphered key information obtained by enciphering the contents key with information about media ID of the first medium as an ID key into a second medium, the contents information processing unit comprising: a memory for temporarily recording information about media ID of the first medium in a condition that the information about the media ID corresponds to data link ID; a data link ID writing means for recording the data link ID into the first medium; an independent ID information forming means for, after the enciphered contents information, the enciphered key information and the data link ID are recorded into the second medium, obtaining information about media ID of the first medium recorded temporarily in the memory based on the data link ID read out from the second medium, forming independent ID information from information about media ID of the first medium and information about media ID of the second medium, and recording the independent ID information in the second medium; and a deleting means for, after the independent ID information is formed, deleting, from the memory, information about media ID of the first medium recorded temporarily.
Still further, to achieve the above object, there is provided a contents information processing unit for processing information about ID of each medium upon recording enciphered contents information and enciphered key information from a first medium which records the enciphered contents information enciphered with a predetermined contents key and enciphered key information obtained by enciphering the contents key with information about media ID of the first medium as an ID key into a second medium, the contents information processing unit comprising: a memory for temporarily recording information about media ID of the first medium and the enciphered key information in a condition that the information about the media ID and the enciphered key information correspond to data link ID; a data link ID writing means for recording the data link ID into the first medium; a memory reading means for, after the enciphered contents information, the enciphered key information and the data link ID are recorded in the second medium, reading out, based on the data link ID read out from the second medium, information about media ID of the first medium recorded temporarily and the enciphered key information from the memory; an enciphered key information comparing means for comparing the enciphered key information read out from the second medium with the enciphered key information read out from the memory by the memory reading means; an independent ID information forming means for, only when the enciphered key information comparing means determines that the two enciphered key informations coincide, forming independent ID information from information about media ID of the second medium and information about media ID of the first medium, and recording the independent ID information in the second medium; and a deleting means for, after the independent ID information is formed, deleting, from the memory, information about media ID of the first medium recorded temporarily and the enciphered key information.
According to a preferred embodiment of the present invention, information about media ID of the first media recorded temporarily in the memory is information based on media ID of the first medium read out from the first medium, and information about media ID of the second media is information based on media ID of the second medium read out from the second medium.
According to another preferred embodiment of the present invention, the independent ID information is differential ID information which is a differential value between media ID of the first medium and media ID of the second medium.
According to still another preferred embodiment of the present invention, the predetermined contents key is common key or public key and the ID key is common key using media ID of the first medium or common key using information obtained by converting the media ID of the first medium with a predetermined function.
To achieve the above object, there is provided a contents information recording method for recording enciphered contents information and enciphered key information from a first medium which records the enciphered contents information enciphered with a predetermined contents key and enciphered key information obtained by enciphering the contents key with information about media ID of the first medium as an ID key into a second medium, the method comprising the steps of: recording temporarily information about the media ID of the first medium in a predetermined memory other than the first and second media, recording the enciphered contents information and the enciphered key information in backup medium from the first medium, and deleting the enciphered key information from the first medium; recording the enciphered contents information and the enciphered key information in the second medium from the backup medium; and recording, in the second medium, independent ID information comprised of information about media ID of the second medium and media ID of the first medium recorded temporarily in the memory, and deleting, from the memory, information about media ID of the first media recorded temporarily.
To achieve the above object, there is provided a contents information processing unit for processing information about ID of each medium upon recording enciphered contents information and enciphered key information from a first medium which records the enciphered contents information enciphered with a predetermined contents key and enciphered key information obtained by enciphering the contents key with information about media ID of the first medium as an ID key through a backup medium into a second medium, the contents information processing unit comprising: a memory for temporarily storing information about media ID of the first medium; an independent ID information forming means for forming independent ID information from information about media ID of the second medium and information about media ID of the first medium recorded temporarily in the memory, and after the enciphered contents information and the enciphered key information are recorded in the second medium from the backup medium, recording the independent ID information in the second medium; and a deleting means for, after the independent ID information is formed, deleting, from the memory, information about media ID of the first medium recorded temporarily.
Further, to achieve the above object, there is provided a backup media, wherein enciphered contents information enciphered with a predetermined contents key, enciphered key information obtained by enciphering the contents key with information about media ID of other media as ID key, and data link ID which is information about link destination to information about media ID of other media are recorded.
To achieve the above object, there is provided a contents information deciphering method for obtaining contents information by decryption from a medium in which enciphered contents information enciphered with a predetermined contents key, enciphered key information obtained by enciphering the contents key with information about media ID of other media as ID key, and independent ID information formed from information about media ID of the other media and information about media ID of a proper medium are recorded, the contents information deciphering method comprising: obtaining information about media ID of the other media from the independent ID information and media ID of the proper media and thereby deciphering the enciphered key information to obtain the contents key; and deciphering the enciphered contents information using the contents key.
According to a preferred embodiment of the present invention, information about media ID of the other media for forming the independent ID information is information based on media ID of other media read out from the other media, and information about media ID of the proper media for forming the independent ID information is information based on media ID of the proper media read out from the proper media.
To achieve the above object, there is provided a contents information deciphering unit for obtaining contents information by decryption from a medium in which enciphered contents information enciphered with a predetermined contents key, enciphered key information obtained by enciphering the contents key with information about media ID of other media as ID key, and independent ID information formed from information about media ID of the other media and information about media ID of a proper medium are recorded, the contents information deciphering unit comprising: a contents key deciphering means for obtaining information about media ID of the other media from the independent ID information and media ID of the proper media and thereby deciphering the enciphered key information to obtain the contents key; and a contents information deciphering means for deciphering the enciphered contents information using the contents key.
According to a preferred embodiment of the present invention, information about media ID of the other media for forming the independent ID information is information based on media ID of other media read out from the other media, and information about media ID of the proper media for forming the independent ID information is information based on media ID of the proper media read out from the proper media.
To achieve the above object, there is provided a media, wherein enciphered contents information enciphered with a predetermined contents key, enciphered key information obtained by enciphering the contents key with information about media ID of other media as ID key, and independent ID information formed from information about media ID of the other media and information about media ID of a proper medium are recorded.
According to a preferred embodiment of the present invention, information about media ID of the other media for forming the independent ID information is information based on media ID of other media read out from the other media, and information about media ID of the proper media for forming the independent ID information is information based on media ID of the proper media read out from the proper media.